drivers/mfd/ipaq-micro.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Compaq iPAQ h3xxx Atmel microcontroller companion support
   4  *
   5  * This is an Atmel AT90LS8535 with a special flashed-in firmware that
   6  * implements the special protocol used by this driver.
   7  *
   8  * based on previous kernel 2.4 version by Andrew Christian
   9  * Author : Alessandro Gardich <gremlin@gremlin.it>
  10  * Author : Dmitry Artamonow <mad_soft@inbox.ru>
  11  * Author : Linus Walleij <linus.walleij@linaro.org>
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/pm.h>
  18 #include <linux/delay.h>
  19 #include <linux/device.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/io.h>
  22 #include <linux/mfd/core.h>
  23 #include <linux/mfd/ipaq-micro.h>
  24 #include <linux/string.h>
  25 #include <linux/random.h>
  26 #include <linux/slab.h>
  27 #include <linux/list.h>
  28
  29 #include <mach/hardware.h>
  30
  31 static void ipaq_micro_trigger_tx(struct ipaq_micro *micro)
  32 {
  33         struct ipaq_micro_txdev *tx = &micro->tx;
  34         struct ipaq_micro_msg *msg = micro->msg;
  35         int i, bp;
  36         u8 checksum;
  37         u32 val;
  38
  39         bp = 0;
  40         tx->buf[bp++] = CHAR_SOF;
  41
  42         checksum = ((msg->id & 0x0f) << 4) | (msg->tx_len & 0x0f);
  43         tx->buf[bp++] = checksum;
  44
  45         for (i = 0; i < msg->tx_len; i++) {
  46                 tx->buf[bp++] = msg->tx_data[i];
  47                 checksum += msg->tx_data[i];
  48         }
  49
  50         tx->buf[bp++] = checksum;
  51         tx->len = bp;
  52         tx->index = 0;
  53
  54         /* Enable interrupt */
  55         val = readl(micro->base + UTCR3);
  56         val |= UTCR3_TIE;
  57         writel(val, micro->base + UTCR3);
  58 }
  59
  60 int ipaq_micro_tx_msg(struct ipaq_micro *micro, struct ipaq_micro_msg *msg)
  61 {
  62         unsigned long flags;
  63
  64         dev_dbg(micro->dev, "TX msg: %02x, %d bytes\n", msg->id, msg->tx_len);
  65
  66         spin_lock_irqsave(&micro->lock, flags);
  67         if (micro->msg) {
  68                 list_add_tail(&msg->node, &micro->queue);
  69                 spin_unlock_irqrestore(&micro->lock, flags);
  70                 return 0;
  71         }
  72         micro->msg = msg;
  73         ipaq_micro_trigger_tx(micro);
  74         spin_unlock_irqrestore(&micro->lock, flags);
  75         return 0;
  76 }
  77 EXPORT_SYMBOL(ipaq_micro_tx_msg);
  78
  79 static void micro_rx_msg(struct ipaq_micro *micro, u8 id, int len, u8 *data)
  80 {
  81         dev_dbg(micro->dev, "RX msg: %02x, %d bytes\n", id, len);
  82
  83         spin_lock(&micro->lock);
  84         switch (id) {
  85         case MSG_VERSION:
  86         case MSG_EEPROM_READ:
  87         case MSG_EEPROM_WRITE:
  88         case MSG_BACKLIGHT:
  89         case MSG_NOTIFY_LED:
  90         case MSG_THERMAL_SENSOR:
  91         case MSG_BATTERY:
  92                 /* Handle synchronous messages */
  93                 if (micro->msg && micro->msg->id == id) {
  94                         struct ipaq_micro_msg *msg = micro->msg;
  95
  96                         memcpy(msg->rx_data, data, len);
  97                         msg->rx_len = len;
  98                         complete(&micro->msg->ack);
  99                         if (!list_empty(&micro->queue)) {
 100                                 micro->msg = list_entry(micro->queue.next,
 101                                                         struct ipaq_micro_msg,
 102                                                         node);
 103                                 list_del_init(&micro->msg->node);
 104                                 ipaq_micro_trigger_tx(micro);
 105                         } else
 106                                 micro->msg = NULL;
 107                         dev_dbg(micro->dev, "OK RX message 0x%02x\n", id);
 108                 } else {
 109                         dev_err(micro->dev,
 110                                 "out of band RX message 0x%02x\n", id);
 111                         if (!micro->msg)
 112                                 dev_info(micro->dev, "no message queued\n");
 113                         else
 114                                 dev_info(micro->dev, "expected message %02x\n",
 115                                          micro->msg->id);
 116                 }
 117                 break;
 118         case MSG_KEYBOARD:
 119                 if (micro->key)
 120                         micro->key(micro->key_data, len, data);
 121                 else
 122                         dev_dbg(micro->dev, "key message ignored, no handle\n");
 123                 break;
 124         case MSG_TOUCHSCREEN:
 125                 if (micro->ts)
 126                         micro->ts(micro->ts_data, len, data);
 127                 else
 128                         dev_dbg(micro->dev, "touchscreen message ignored, no handle\n");
 129                 break;
 130         default:
 131                 dev_err(micro->dev,
 132                         "unknown msg %d [%d] %*ph\n", id, len, len, data);
 133                 break;
 134         }
 135         spin_unlock(&micro->lock);
 136 }
 137
 138 static void micro_process_char(struct ipaq_micro *micro, u8 ch)
 139 {
 140         struct ipaq_micro_rxdev *rx = &micro->rx;
 141
 142         switch (rx->state) {
 143         case STATE_SOF: /* Looking for SOF */
 144                 if (ch == CHAR_SOF)
 145                         rx->state = STATE_ID; /* Next byte is the id and len */
 146                 break;
 147         case STATE_ID: /* Looking for id and len byte */
 148                 rx->id = (ch & 0xf0) >> 4;
 149                 rx->len = (ch & 0x0f);
 150                 rx->index = 0;
 151                 rx->chksum = ch;
 152                 rx->state = (rx->len > 0) ? STATE_DATA : STATE_CHKSUM;
 153                 break;
 154         case STATE_DATA: /* Looking for 'len' data bytes */
 155                 rx->chksum += ch;
 156                 rx->buf[rx->index] = ch;
 157                 if (++rx->index == rx->len)
 158                         rx->state = STATE_CHKSUM;
 159                 break;
 160         case STATE_CHKSUM: /* Looking for the checksum */
 161                 if (ch == rx->chksum)
 162                         micro_rx_msg(micro, rx->id, rx->len, rx->buf);
 163                 rx->state = STATE_SOF;
 164                 break;
 165         }
 166 }
 167
 168 static void micro_rx_chars(struct ipaq_micro *micro)
 169 {
 170         u32 status, ch;
 171
 172         while ((status = readl(micro->base + UTSR1)) & UTSR1_RNE) {
 173                 ch = readl(micro->base + UTDR);
 174                 if (status & UTSR1_PRE)
 175                         dev_err(micro->dev, "rx: parity error\n");
 176                 else if (status & UTSR1_FRE)
 177                         dev_err(micro->dev, "rx: framing error\n");
 178                 else if (status & UTSR1_ROR)
 179                         dev_err(micro->dev, "rx: overrun error\n");
 180                 micro_process_char(micro, ch);
 181         }
 182 }
 183
 184 static void ipaq_micro_get_version(struct ipaq_micro *micro)
 185 {
 186         struct ipaq_micro_msg msg = {
 187                 .id = MSG_VERSION,
 188         };
 189
 190         ipaq_micro_tx_msg_sync(micro, &msg);
 191         if (msg.rx_len == 4) {
 192                 memcpy(micro->version, msg.rx_data, 4);
 193                 micro->version[4] = '\0';
 194         } else if (msg.rx_len == 9) {
 195                 memcpy(micro->version, msg.rx_data, 4);
 196                 micro->version[4] = '\0';
 197                 /* Bytes 4-7 are "pack", byte 8 is "boot type" */
 198         } else {
 199                 dev_err(micro->dev,
 200                         "illegal version message %d bytes\n", msg.rx_len);
 201         }
 202 }
 203
 204 static void ipaq_micro_eeprom_read(struct ipaq_micro *micro,
 205                                    u8 address, u8 len, u8 *data)
 206 {
 207         struct ipaq_micro_msg msg = {
 208                 .id = MSG_EEPROM_READ,
 209         };
 210         u8 i;
 211
 212         for (i = 0; i < len; i++) {
 213                 msg.tx_data[0] = address + i;
 214                 msg.tx_data[1] = 1;
 215                 msg.tx_len = 2;
 216                 ipaq_micro_tx_msg_sync(micro, &msg);
 217                 memcpy(data + (i * 2), msg.rx_data, 2);
 218         }
 219 }
 220
 221 static char *ipaq_micro_str(u8 *wchar, u8 len)
 222 {
 223         char retstr[256];
 224         u8 i;
 225
 226         for (i = 0; i < len / 2; i++)
 227                 retstr[i] = wchar[i * 2];
 228         return kstrdup(retstr, GFP_KERNEL);
 229 }
 230
 231 static u16 ipaq_micro_to_u16(u8 *data)
 232 {
 233         return data[1] << 8 | data[0];
 234 }
 235
 236 static void __init ipaq_micro_eeprom_dump(struct ipaq_micro *micro)
 237 {
 238         u8 dump[256];
 239         char *str;
 240
 241         ipaq_micro_eeprom_read(micro, 0, 128, dump);
 242         str = ipaq_micro_str(dump, 10);
 243         if (str) {
 244                 dev_info(micro->dev, "HW version %s\n", str);
 245                 kfree(str);
 246         }
 247         str = ipaq_micro_str(dump+10, 40);
 248         if (str) {
 249                 dev_info(micro->dev, "serial number: %s\n", str);
 250                 /* Feed the random pool with this */
 251                 add_device_randomness(str, strlen(str));
 252                 kfree(str);
 253         }
 254         str = ipaq_micro_str(dump+50, 20);
 255         if (str) {
 256                 dev_info(micro->dev, "module ID: %s\n", str);
 257                 kfree(str);
 258         }
 259         str = ipaq_micro_str(dump+70, 10);
 260         if (str) {
 261                 dev_info(micro->dev, "product revision: %s\n", str);
 262                 kfree(str);
 263         }
 264         dev_info(micro->dev, "product ID: %u\n", ipaq_micro_to_u16(dump+80));
 265         dev_info(micro->dev, "frame rate: %u fps\n",
 266                  ipaq_micro_to_u16(dump+82));
 267         dev_info(micro->dev, "page mode: %u\n", ipaq_micro_to_u16(dump+84));
 268         dev_info(micro->dev, "country ID: %u\n", ipaq_micro_to_u16(dump+86));
 269         dev_info(micro->dev, "color display: %s\n",
 270                  ipaq_micro_to_u16(dump+88) ? "yes" : "no");
 271         dev_info(micro->dev, "ROM size: %u MiB\n", ipaq_micro_to_u16(dump+90));
 272         dev_info(micro->dev, "RAM size: %u KiB\n", ipaq_micro_to_u16(dump+92));
 273         dev_info(micro->dev, "screen: %u x %u\n",
 274                  ipaq_micro_to_u16(dump+94), ipaq_micro_to_u16(dump+96));
 275 }
 276
 277 static void micro_tx_chars(struct ipaq_micro *micro)
 278 {
 279         struct ipaq_micro_txdev *tx = &micro->tx;
 280         u32 val;
 281
 282         while ((tx->index < tx->len) &&
 283                (readl(micro->base + UTSR1) & UTSR1_TNF)) {
 284                 writel(tx->buf[tx->index], micro->base + UTDR);
 285                 tx->index++;
 286         }
 287
 288         /* Stop interrupts */
 289         val = readl(micro->base + UTCR3);
 290         val &= ~UTCR3_TIE;
 291         writel(val, micro->base + UTCR3);
 292 }
 293
 294 static void micro_reset_comm(struct ipaq_micro *micro)
 295 {
 296         struct ipaq_micro_rxdev *rx = &micro->rx;
 297         u32 val;
 298
 299         if (micro->msg)
 300                 complete(&micro->msg->ack);
 301
 302         /* Initialize Serial channel protocol frame */
 303         rx->state = STATE_SOF;  /* Reset the state machine */
 304
 305         /* Set up interrupts */
 306         writel(0x01, micro->sdlc + 0x0); /* Select UART mode */
 307
 308         /* Clean up CR3 */
 309         writel(0x0, micro->base + UTCR3);
 310
 311         /* Format: 8N1 */
 312         writel(UTCR0_8BitData | UTCR0_1StpBit, micro->base + UTCR0);
 313
 314         /* Baud rate: 115200 */
 315         writel(0x0, micro->base + UTCR1);
 316         writel(0x1, micro->base + UTCR2);
 317
 318         /* Clear SR0 */
 319         writel(0xff, micro->base + UTSR0);
 320
 321         /* Enable RX int, disable TX int */
 322         writel(UTCR3_TXE | UTCR3_RXE | UTCR3_RIE, micro->base + UTCR3);
 323         val = readl(micro->base + UTCR3);
 324         val &= ~UTCR3_TIE;
 325         writel(val, micro->base + UTCR3);
 326 }
 327
 328 static irqreturn_t micro_serial_isr(int irq, void *dev_id)
 329 {
 330         struct ipaq_micro *micro = dev_id;
 331         struct ipaq_micro_txdev *tx = &micro->tx;
 332         u32 status;
 333
 334         status = readl(micro->base + UTSR0);
 335         do {
 336                 if (status & (UTSR0_RID | UTSR0_RFS)) {
 337                         if (status & UTSR0_RID)
 338                                 /* Clear the Receiver IDLE bit */
 339                                 writel(UTSR0_RID, micro->base + UTSR0);
 340                         micro_rx_chars(micro);
 341                 }
 342
 343                 /* Clear break bits */
 344                 if (status & (UTSR0_RBB | UTSR0_REB))
 345                         writel(status & (UTSR0_RBB | UTSR0_REB),
 346                                micro->base + UTSR0);
 347
 348                 if (status & UTSR0_TFS)
 349                         micro_tx_chars(micro);
 350
 351                 status = readl(micro->base + UTSR0);
 352
 353         } while (((tx->index < tx->len) && (status & UTSR0_TFS)) ||
 354                  (status & (UTSR0_RFS | UTSR0_RID)));
 355
 356         return IRQ_HANDLED;
 357 }
 358
 359 static const struct mfd_cell micro_cells[] = {
 360         { .name = "ipaq-micro-backlight", },
 361         { .name = "ipaq-micro-battery", },
 362         { .name = "ipaq-micro-keys", },
 363         { .name = "ipaq-micro-ts", },
 364         { .name = "ipaq-micro-leds", },
 365 };
 366
 367 static int __maybe_unused micro_resume(struct device *dev)
 368 {
 369         struct ipaq_micro *micro = dev_get_drvdata(dev);
 370
 371         micro_reset_comm(micro);
 372         mdelay(10);
 373
 374         return 0;
 375 }
 376
 377 static int __init micro_probe(struct platform_device *pdev)
 378 {
 379         struct ipaq_micro *micro;
 380         int ret;
 381         int irq;
 382
 383         micro = devm_kzalloc(&pdev->dev, sizeof(*micro), GFP_KERNEL);
 384         if (!micro)
 385                 return -ENOMEM;
 386
 387         micro->dev = &pdev->dev;
 388
 389         micro->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
 390         if (IS_ERR(micro->base))
 391                 return PTR_ERR(micro->base);
 392
 393         micro->sdlc = devm_platform_ioremap_resource(pdev, 1);
 394         if (IS_ERR(micro->sdlc))
 395                 return PTR_ERR(micro->sdlc);
 396
 397         micro_reset_comm(micro);
 398
 399         irq = platform_get_irq(pdev, 0);
 400         if (irq < 0)
 401                 return -EINVAL;
 402         ret = devm_request_irq(&pdev->dev, irq, micro_serial_isr,
 403                                IRQF_SHARED, "ipaq-micro",
 404                                micro);
 405         if (ret) {
 406                 dev_err(&pdev->dev, "unable to grab serial port IRQ\n");
 407                 return ret;
 408         } else
 409                 dev_info(&pdev->dev, "grabbed serial port IRQ\n");
 410
 411         spin_lock_init(&micro->lock);
 412         INIT_LIST_HEAD(&micro->queue);
 413         platform_set_drvdata(pdev, micro);
 414
 415         ret = mfd_add_devices(&pdev->dev, pdev->id, micro_cells,
 416                               ARRAY_SIZE(micro_cells), NULL, 0, NULL);
 417         if (ret) {
 418                 dev_err(&pdev->dev, "error adding MFD cells");
 419                 return ret;
 420         }
 421
 422         /* Check version */
 423         ipaq_micro_get_version(micro);
 424         dev_info(&pdev->dev, "Atmel micro ASIC version %s\n", micro->version);
 425         ipaq_micro_eeprom_dump(micro);
 426
 427         return 0;
 428 }
 429
 430 static const struct dev_pm_ops micro_dev_pm_ops = {
 431         SET_SYSTEM_SLEEP_PM_OPS(NULL, micro_resume)
 432 };
 433
 434 static struct platform_driver micro_device_driver = {
 435         .driver   = {
 436                 .name   = "ipaq-h3xxx-micro",
 437                 .pm     = &micro_dev_pm_ops,
 438                 .suppress_bind_attrs = true,
 439         },
 440 };
 441 builtin_platform_driver_probe(micro_device_driver, micro_probe);